VB here are .02 from a fellow Commonwealther:
You made the right call. Some officials think that getting the OB correct is the most difficult call in a game.
I was brought up in the school that most rebounding fouls should come from the C and/or T. It is very difficult for an L to see a push in the back.
What the other officials MIGHT have been thinking was that you saw the push in the back, and passed on it in favor of just awarding the ball to A. When you gave it to B, they were *&$%ed. (and you SHOULD have given it to B based on what you saw)
As for addressing the guys later, I would have said something to the effect "yeah, if I had seen the push I might have given it to A, but since all I saw was A touch it last I had to go with that." It is VERY non committal and should keep you out of any hotwater with any local politics.
Drop me a line if you head over to the Central part of the Commonwealth!